In this work, deep
eutectic solvents (DESs) composed of choline
chloride, acetylcholine chloride or tetrabutylammonium chloride, and
1,2-propanediol were used as a liquid phase for polypropylene-based
supported liquid membranes (SLMs) and evaluated for the separation
of carbon dioxide from CO2/N2 mixtures. Fourier
transform infrared spectra were obtained to confirm DES formation,
and the thermal stability of solvents was investigated using thermogravimetric
analysis. The physicochemical properties of DESs and carbon dioxide
solubility were determined in a temperature range of 293.15–313.15
K. The effects of the hydrogen bond acceptor structure and the acceptor/donor
molar ratio in regard to properties and CO2 separation
potential were discussed. The permeability of CO2 and N2 in DES-based SLMs was determined, and the ideal CO2/N2 selectivity was calculated. The gas permeation results
of the 1,2-propanediol-based DES-based supported liquid membranes
showed that the permeability of CO2 varied from 86 to 152
barrers in 293.15 K. Similarly, the ideal CO2/N2 selectivity varied from 21 to 30. The performance of DES–SLMs
was compared with the competing imidazolium-based supported ionic
liquid membranes and proved DES–SLMs as a promising alternative
considering their green potential and comparable gas separation performance.